This invention relates to a method and an apparatus for its practice, integrated in a carding machine. The apparatus is of the known type in which the staple (fiber length) and nep number are measured at the output of the carding machine and regulation is effected based on the sensed signals.
In a known process as disclosed in published European patent application Ser. No. 0 410 429, at the output of the carding machine the fiber length and nep number are measured; the measured values must correspond to precisely defined criteria. If it is not feasible to maintain such values within the predetermined magnitudes by regulating the carding machine, an attempt is first made to improve such values by setting the fine cleaning machine anew. If again, such an attempt is unsuccessful, it is necessary to change the mixing ratio which has to be performed by an appropriate control of the bale opener; this also affects the bale stock.
In such a method the individual magnitudes, that is, the value of nep number and fiber length are measured and a new setting of the carding machine is effected based on the individual magnitudes of nep number and fiber length. By virtue of a certain card setting either the nep number may be reduced or, by means of a different card setting, the fiber length may be changed. Although a significant reduction in the nep number might be obtained by changing the setting magnitude of, for example, a card setting, a substantial negative change of the fiber length may simultaneously occur, or conversely. Conventional processes are based on the assumption that an improvement of both individual measuring magnitudes, namely the reduction of the nep number and the improvement in the staple (fiber length) may not be achieved merely by setting the carding machine, but rather, the mixing ratio of the fiber material must also be changed.